You are entitled to "uninterrupted" FMLA leave so if you don't want to do this work while you're on leave, your boss can't require you to. When you contact the boss, do be careful about the tone of your reply. (a) He's probably in a real bind with you out, and (b) it won't do you any good to aggravate him. You can tell him that while you wish you weren't laid up, you are on medical leave, recuperating from surgery, and just aren't able to do any work right now. If he gives you a hard time and insists you do the work, contact HR again. If they won't get involved, then contact whomever HR reports to.
There's no ambiguity about this under the law. Your employer cannot require you to work while on FMLA.
There's no ambiguity about this under the law. Your employer cannot require you to work while on FMLA.